While we had the option to split roles between servers in previous versions of Exchange Server, we don't have that anymore. Instead, the Exchange server roles are divided between Mailbox and Edge Transport server roles now. As you will understand, the previous role called Client Access Role is not a role anymore; instead, it's renamed to Client Access services, which makes sense when thinking about it. It basically serves our end users with its services.
Under the hood of Client Access services, we still have underlying services for Outlook on the Web/Outlook Web App (OWA), ActiveSync, POP3, and IMAP4.
By default, all MAPI clients now connects by using MAPI over HTTP instead of the MAPI over RPC version. This is now enabled by default in Exchange 2016; the MAPI over RPC has now been discontinued.
With the new CAS architecture, the connection procedure has...
